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fertilizer in poolwater

11-16-2009, 06:14 AM

Our water has so much plant nutriens in it that the poolwater stay green.We have shock treat with chlorine, which kill the alge, but as soon as the chlorine level drop to the required level the pool become green within a day.
We do not have access to water with low plant nutriens. Please help before i fill the pool with soil. Any method to take out the nutriens?
Regards
Neels

Comment

I do not know what the current wisdom or recommendations, (as this was close to 50 years ago), and can not even tell you the amounts, but when we were kids, we had a old supply tank that was supplied by a windmill, (about 15 feet by 15 feet and about 6 feet deep) we swam in in the summer time.

It was not nitrates in the water but the Sun that would create the algae growth, I do not know why some people have extreme heavy growth in the stock tanks or light growth, (in our situation).
but my mother wrote the Ag collage and asked what to use,( as we swam in it and watered the cattle with the water), as a treatment to the water and the answer was Copper sulfate, in small quantiles, I remember my mother using just a few ounces ever week in the tank, (this tank was continuous feed as the tank had some leaks and it feed the stock tank across the road for cattle).
I do not know if this is still a approved method or not, the copper sulfate works as a plant killer (herbicide),
it would probably be best to use a commercial algaecide instead of making your own, but I do see that some algaecide use copper based products, but in what ratio or amounts, I do not know, (copper sulfate is used a root killer in some sewer root products),

An algaecide does nothing to remove the nitrate or the phosphate, it just kills the growth of plant matter,

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what looks like some good info on the different types of algae and some tips on controlling them,

I would do some Google searches on "algaecides" and "control of algae".

maybe jump on some pool forums and read and search the back posts,

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Just a question here, but if the pool water is high in nitrates and phosphates, what is your drinking water?
high levels of nitrates can be harmful to young children, and especially harmful to the fetus of a pregnant woman, it can cause abortions and other problems,
If you have a true nitrate problem, I hope you have a clean supply of drinking water for your family's sake, (the town where my Daughter lives in, has had much problem with nitrates and She has miscarried a number of times after they first moved there, and was not able to carry a child until they stopped drinking the towns water, and drinking water from other sources.

I would be less worried about the pool and more concerned about the water I was drinking, you can swim in green water (add a few fish and that makes it more exciting as the brush up against your legs), but nitrates can be very harmful to young growing bodies, (and probably not the best for old bodies).

Push sticks/blocks Save Fingers
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Comment

If you have been shocking the pool continuously with most powder shocks, and using tablet chlorine, your CYA level is probably too high. Most shocks and stabilized chlorine tabs (almost all are stabilized) contain CYA (cyanuric acid) as the stabilizer. When your stabilizer level gets too high, your chlorine level requirement gets much higher (your water is over stabilized so much more chlorine is required to have an effect. Check or have your stabilizer level checked. If your problem is truly phosphates/nitrates, there are some pricey chemicals to get rid of them, but most of the time an algae problem is due to having to much stabilizer in the water causing your chlorine to have no effect. Normal CYA levels should be 30-50 and keep your free chlorine between 3-5. If your cya is 150 then you would need to keep your free chlorine around 10 ppm and take it up to 20+ and hold it there for several days to kill the algae bloom. The only way to get rid of some CYA is to partial drain and refill. Go to this forum http://www.troublefreepool.com/ and check it out. It is the best forum I have found, and have found answers to all my questions from the search feature, never had to ask any! This is not a spam - I am a pool owner who has been thru the whole algae bloom thing.

As far as unstabilized chlorine goes, good ol Clorox or the generic. MUST be the unscented , non fabric softening type. Look for a generic brand with 6% Sodium Hypochlorite) as it is much more economical - some of the cheapies are only 3% so read the back of the label. 1 gal will raise chlorine 6 ppm per 10000 gal of pool water.

Comment

Hmmm... No pool expert, buy wired a bunch of them. The new rage seems to be a Salt water generator. My brother has one, seems relatively easy to use and controls the water without adding anything chemicals to the pool except salt in the begining of the season.

Comment

The copper sulfate recommended above works as an algaecide, but can stain certain types of pools. I think the plaster pools are very vulnerable to this. Maintaining chlorine at shock levels for several days will kill the algae very effectively. Check out the website I mentioned above and find out what your chlorine needs to be at. Have a thorough water test run especially for CYA and phosphate levels. Your phosphate levels may be high but I suspect you are not maintaining the shock enough. When algae blooms, you will use a tremendous amount of chlorine. You have to test and add chlorine 3-4 times/day and hold the shock level for 3-4 days. I suspect you are knocking the algae back and not quite eliminating it. Use Muriatic acid if your ph goes thru the roof, as it will. If your ph is high, that also reduces the effectiveness of your Chlorine.